In Squaresoft's 1997 Final Fantasy VII, the Wall Market is a district in the slums of Midgar.
The scene in the Wall Market, which takes about twenty minutes to get through, is probably the first scene in the game where it is clear that Square hasn't just used the Playstation's capacities to move a game's graphics foreward in leaps and bounds, but was also going to challenge what was considered morally acceptable in a video game. The Wall Market, like the rest of Midgar, is a dirty, worn out slum with foul mouthed people. On top of that, it has a brothel, and is run by the Mafia.
All of this is just set up for the scene that takes place here, where Aeris Gainsborough and Cloud Strife must sneak into the brothel. The problem here, of course, is that Cloud is a guy, and before he can get in, he has to dress like a woman. So for twenty minutes of the game, you must walk around the slum, including a brothel that has hints of homosexuality and Satanism and a gymnasium full of transvestites. For years, Nintendo had kept a strict code that prevented any reference to sex or religion in games. By making a sequence where the point was to dress up a male character as a woman to sneak into a brothel, Square really set a new standard for adult content in videogames.
The slum itself is rather derivative, but as in everything in Final Fantasy games, it is derivative in a unique way. The odd mix of future developments and gritty noir owe a lot to Gun Dream, but then most of Japanese pop culture for the past ten years owes a lot to Gun Dream. The slum has perhaps a few dozen different people to talk to, that within the confines of the few sentences they speak, show the complexity of an oppressive urban culture. There is quite a bit going on in the slum, especially if you know Hanzi, for example, the welcome mat in the brothel says Haose Nan (Men who are fond of lust). The Wall Market is a great example of how the video game medium can provide atmosphere and present complex puzzles.